1. Field of the Invention
The present invention relates to apparati and methods for cooling of electronic components and, more particularly, for endothermic cooling utilizing a composition of matter, such as a salt, which is capable of providing an endothermic reaction when placed in solution.
2. Description of Related Art and Other Considerations
In any electronic equipment, the temperature of each component will rise until it is hot enough to transfer its internally generated heat to the surroundings. If the cooling design is not adequate, the component itself will become overly hot, as it attempts to transfer heat from itself, and will malfunction or even destroy itself. Therefore, many implementations have been designed to conduct heat from the electronic equipment or individual component to the surrounding environment, sometimes aided by cooling fins, by such methods as radiation and natural convection, forced air cooling, forced liquid cooling, and liquid evaporation.
In some cases, the electronic component itself is at a higher temperature than the surroundings. Because heat flows from hot to cold bodies, such components can be cooled by one of above-mentioned methods. In other cases, however, electronic performance can only be achieved by lowering the temperature of the electronic component below that of its surroundings, such as by refrigeration. In the refrigeration process, heat does not flow from the electronic component, but is pumped or otherwise removed by the refrigeration system from the cold component to the hot surroundings. Examples of refrigeration systems for electronic equipment include refrigerated cooling air or cooling liquid, refrigerated heat sinks, and thermoelectric coolers. Each of these refrigeration schemes requires input energy for operation and eventual heat dissipation to the environment.
There are disadvantages associated with conventional cooling arrangements. Their use adds weight and expense to the system in which they are used. For airborne and space vehicles, and to a lesser extent other transportable mechanisms, weight is a very important concern, especially where the overall weight must be apportioned between the payload and the supporting system therefor, whether defined in terms of its propulsion system or otherwise. It is obvious, therefore, that, if the weight of the cooling system can be reduced, the payload can be proportionately increased. This consideration applies not only to the vehicle itself, but also to the transporter for the vehicle. For example, a missile carries a payload or warhead to a target. If the refrigeration system of the missile can be reduced in weight, its warhead or guidance system can be increased. Therefore, for a given weight of missile, it becomes possible to maximize its use. On the other hand, it also becomes possible to decrease the entire weight of the missile and, therefore, to enable the aircraft to add additional equipment or other missiles. These weight considerations become particularly important with respect to mechanisms which do not require greater than a single use, such as is particularly true with respect to missiles.
It is equally obvious that a decrease in weight not only makes the vehicle more cost efficient but also enables the additional costs of special cooling equipment to be reduced, at times to significant degrees.
Therefore, in many cases, expensive and reusable refrigeration methods and mechanisms are not needed, and it becomes advantageous if such needs and attendant hardware, such as external cooling fins, can be eliminated.